Return-Path: Received: (qmail 23139 invoked from network); 7 Dec 2000 20:15:17 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by extortion.plus.net with SMTP; 7 Dec 2000 20:15:17 -0000 Received: (qmail 15519 invoked from network); 7 Dec 2000 20:17:25 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 7 Dec 2000 20:17:25 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #1) id 1447ON-0003kl-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 07 Dec 2000 20:11:47 +0000 Received: from mta1-rme.xtra.co.nz ([203.96.92.1]) by post.thorcom.com with esmtp (Exim 3.16 #1) id 1447OL-0003ka-00 for rsgb_lf_group@blacksheep.org; Thu, 07 Dec 2000 20:11:46 +0000 Received: from xtr743187 ([202.27.181.78]) by mta1-rme.xtra.co.nz with SMTP id <20001207201105.CKZQ8076195.mta1-rme.xtra.co.nz@xtr743187> for ; Fri, 8 Dec 2000 09:11:05 +1300 Message-ID: <009e01c0608a$62a1d420$21b21bca@xtr743187> From: "Vernall" To: rsgb_lf_group@blacksheep.org References: <65AECDF1F89AD411900400508BFC869F0D7469@pdw-mail-1.dera.gov.uk> Subject: LF: Re: Re:amplifiers Date: Fri, 8 Dec 2000 09:13:35 +1300 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2919.6600 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: ----- Original Message ----- > My main > driver for using a 340V rail was the need to not have to have a separate > PA. A 50V 25A PSU is fine if you can get one - I have an old telephone > exchange PSU - but normally it is a big beast if you have to make one > up, so multiple bridged lower voltage PAs is a complex way to go if > building from scratch, even if a lot safer. If rectified mains power supplies are to be considered, one way to improve safety is to use a 1:1 isolating transformer, which are fairly available. It should at least be used for doing development or any testing. 73, Bob